Mining bit puller with striking pad

ABSTRACT

A mining bit puller having a striking pad is disclosed. The puller has a plate with two forks at a front end and a striking pad at a back end. In one embodiment, the forks are generally wedge shaped, and the puller includes a handle extending at an angle from the top of the bit puller plate. During mining tool bit changeout operations, the pad may be struck with a hammer or other tool in order to force the forks between a collar of the tool bit and its mounting block to pull the tool bit out of the block.

FIELD OF THE INVENTION

The present invention relates to mining bit extractors, and moreparticularly relates to a puller having a striking pad.

BACKGROUND INFORMATION

Mining tools include generally conical tool bits which are removablyinstalled in mounting blocks attached to rotating drums. When the toolbits become worn, they are pulled from their blocks and replaced. Pullertools are used to extract the tool bits. One type of puller haswedge-shaped forks which slide between a collar of the tool bit and themounting block to force the bit out of the block. In order to insert theforks, it is often necessary to strike the back of the puller. However,in conventional pullers, striking of the puller with a hammer or othertool can cause flying metal shards.

SUMMARY OF THE INVENTION

The present invention provides a mining bit puller having a strikingpad. The puller has a plate with two forks at a front end and a strikingpad at a back end. During mining tool bit changeout operations, the padmay be struck with a hammer or other tool in order to force the forksbetween a collar of the tool bit and its mounting block to pull the toolbit out of the block.

An aspect of the present invention is to provide a mining bit puller forextracting mining tool bits. The puller comprises a bit puller plateincluding two forks at a front end of the plate and a striking pad at aback end of the plate. In one embodiment, the forks are generally wedgeshaped, and the puller includes a handle extending at an angle from thetop of the bit puller plate.

Another aspect of the present invention is to provide a mining bitpuller for extracting mining tool bits, wherein the puller comprises abit puller plate including two forks at a front end of the plate, and aback end of the plate is structured and arranged to receive a strikingpad.

A further aspect of the present invention is to provide a striking padfor a mining bit puller, wherein the striking pad comprises a strikingsurface, and means for connecting the striking pad to the puller.

These and other aspects of the present invention will be more apparentfrom the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a mining bit puller including a strikingpad in accordance with an embodiment of the present invention.

FIG. 2 is a side view of the mining bit puller of FIG. 1.

FIG. 3 is a rear view of the mining bit puller of FIG. 1.

FIG. 4 is a top view of a bit puller plate with a portion of the plateand a striking pad shown in section in accordance with an embodiment ofthe present invention.

FIG. 5 is a side view of the bit puller plate of FIG. 4 with a portionof the plate and the striking pad shown in section.

FIG. 6 is a rear view of a bit puller plate including an annular recessand threaded hole in accordance with an embodiment of the presentinvention.

FIG. 7 is a side view of a puller striking pad in accordance with anembodiment of the present invention.

FIG. 8 is an isometric view showing the rear of a bit puller plateincluding a rectangular striking pad in accordance with anotherembodiment of the present invention.

DETAILED DESCRIPTION

FIGS. 1-3 illustrate a mining bit puller 10 having a bit puller plate 20in accordance with an embodiment of the present invention. The bitpuller plate 20 includes a mid section 22, a front end having twogenerally wedge-shaped forks 24 a and 24 b, and a back end 26. The forks24 a and 24 b are structured and arranged to be inserted between amining tool bit and its mounting block in order to remove the tool bitfrom its block. A handle 28 extends at an angle A from the top of thebit puller plate 20. For example, the handle 28 may be oriented at anangle A of less than 90 degrees with respect to a plane defined by thebit puller plate 20, e.g., from about 40 or 50 degrees to about 70 or 80degrees. A hand grip 29 is provided at the end of the handle 28. The bitpuller plate 20 and the handle 28 may be made of any suitable materialsuch as steel. The bit puller plate 20 and handle 28 may be weldedtogether. The hand grip 29 may be made of any suitable material such asrubber or plastic.

In accordance with the present invention, a striking pad 30 is providedat the back end 26 of the bit puller plate 20. The striking pad 30 ispreferably made of a resilient material such as polymers, plastics,elastomers, rubber, soft metals, leather, wood products, natural fibersor the like. When the puller 10 is used for extracting mining tool bits(not shown), the wedge-shaped forks 24 a and 24 b may be forced betweena collar of the tool bit and its mounting block by striking the pad 30with a hammer or other suitable tool. The striking pad 30 thus should bemade of a material capable of withstanding repeated striking forces.

The striking pad 30 may be fastened to the back end 26 of the bit pullerplate 20 by any suitable means such as mechanical fasteners, pressfittings, welding, adhesives and the like. FIGS. 4-7 illustrateembodiments of the present invention in which the striking pad 30 isfastened to the back end 26 of the bit puller plate 20 by mechanicalfastening. In this embodiment, the striking pad 30 has a circular crosssection and includes a circular extension 32 extending in an axialdirection from the striking pad 30. The extended portion 32 is receivedin an annular recess 27 in the back 26 of the bit puller plate 20.

As shown in FIG. 4, the body of the striking pad 30 has an axial lengthL₁ which is greater than an axial length L₂ of the extended portion 32.For example, the axial length L₁ may be from about 0.5 to about 10 timesgreater than the axial length L₂ of the extended portion 32. The axiallength L₁ is typically from about 0.25 to about 1.5 inches, while theaxial length L₂ of the extended portion 32 is typically from zero toabout 0.75 inch.

As shown in FIG. 4, the body of the striking pad 30 has a diameter D₁which is greater than a diameter D₂ of the extended portion 32. Forexample, the diameter D₁ may be from about 0.1 to about 5 times greaterthan the diameter D₂ of the extended portion 32. The diameter D₁ maytypically be from about 0.5 to about 2 or 3 inches, while the diameterD₂ may typically be from about 0.5 to about 2 inches.

As shown most clearly in FIGS. 4, 5 and 7, the striking pad 30 includesa threaded bolt 36 which may be attached to a metal plate 34 at leastpartially embedded in the striking pad 30. The metal plate 34 may beintegrally formed with the threaded shaft 36, e.g., the plate 34 maycomprise a bolt head.

As shown most clearly in FIGS. 4-6, the bit puller plate 20 includes anannular recess 27 with a threaded hole 25 at the center thereof. Theextended portion 32 of the striking pad 30 fits within the annularrecess 27 of the bit puller plate 20. The threaded shaft 36 of thestriking pad 30 may be threaded into the hole 25 of the bit puller plate20. Although the striking pad 30 is mechanically fastened to the bitpuller plate 20 in the embodiment shown in FIGS. 4-7, any other suitablemeans of attachment may be used in accordance with the presentinvention.

FIG. 8 illustrates the rear of a bit puller plate 40 in accordance withanother embodiment of the present invention. The embodiment shown inFIG. 8 is similar to the previous embodiments, except a generallyrectangular striking pad 42 is used instead of a circular striking pad.The rectangular striking pad 42 may be attached to the back end 26 ofthe bit puller plate 40 by any suitable means such as adhesives, pressfittings, mechanical fasteners, welding and the like. The rectangularstriking pad 42 may include an extended portion (not shown) which isreceived in a corresponding recess (not shown) in the back end 26 of thebit puller plate 40. For example, the rectangular striking pad 42 mayhave a rectangular extension or, alternatively, a circular extensionsimilar to the circular extension 32 shown in FIGS. 4, 5 and 7. Inaddition to rectangular and circular cross sections, any other suitableshape of striking pad may be used in accordance with the presentinvention.

Although the pullers shown in the figures have generally wedge shapedforks 24 a and 24 b, other fork shapes may be used in accordance withthe present invention. For example, the forks may be substantially flatinstead of wedge shaped. Furthermore, although the pullers illustratedin the figures include a handle 28 extending at an angle from the top ofthe bit puller plate 20, other handle arrangements may be used inaccordance with the present invention. For example, a handle may extendfrom the back end of the bit puller plate. In this case, the strikingpad may be mounted at the end of the handle at the back end of the bitpuller plate.

Whereas particular embodiments of this invention have been describedabove for purposes of illustration, it will be evident to those skilledin the art that numerous variations of the details of the presentinvention may be made without departing from the invention as defined inthe appended claims.

1. A mining bit puller for extracting mining tool bits, the pullercomprising a bit puller plate including two forks at a front end of theplate and a striking pad at a back end of the plate.
 2. The mining bitpuller of claim 1, wherein the striking pad comprises a resilientmaterial.
 3. The mining bit puller of claim 1, wherein the striking padcomprises a polymer material.
 4. The mining bit puller of claim 1,wherein the striking pad is mechanically fastened to the bit pullerplate.
 5. The mining bit puller of claim 4, wherein the striking padcomprises a threaded bolt extending into a threaded hole in the bitpuller plate.
 6. The mining bit puller of claim 1, wherein the strikingpad is fastened to the bit puller plate by an adhesive.
 7. The miningbit puller of claim 1, wherein the striking pad is fastened to the bitpuller plate by a press fitting.
 8. The mining bit puller of claim 1,wherein at least a portion of the striking pad is inserted into a recessin the bit puller plate.
 9. The mining bit puller of claim 1, whereinthe striking pad comprises an extended portion received with a recess inthe bit puller plate.
 10. The mining bit puller of claim 9, wherein theextended portion of the striking pad has a circular cross section. 11.The mining bit puller of claim 9, wherein the extended portion of thestriking pad has an axial length smaller than an axial length of theremainder of the striking pad.
 12. The mining bit puller of claim 1,wherein the striking pad has a circular cross section.
 13. The miningbit puller of claim 1, wherein the striking pad has a rectangular crosssection.
 14. The mining bit puller of claim 1, wherein the striking padcomprises a metal plate and a resilient material attached to the metalplate.
 15. The mining bit puller of claim 14, wherein the resilientmaterial at least partially surrounds the metal plate.
 16. The miningbit puller of claim 14, wherein the metal plate of the striking pad ismechanically fastened to the bit puller plate.
 17. The mining bit pullerof claim 16, further comprising a threaded bolt attached to the metalplate of the striking pad and received in a threaded hole in the bitpuller plate.
 18. The mining bit puller of claim 14, wherein the metalplate of the striking pad is welded to the bit puller plate.
 19. Themining bit puller of claim 1, wherein the forks are generally wedgeshaped.
 20. The mining bit puller of claim 1, further comprising ahandle extending from the bit puller plate.
 21. The mining bit puller ofclaim 20, wherein the handle extends from a top surface of the bitpuller plate at an angle of less than 90 degrees with respect to a planedefined by the bit puller plate.
 22. The mining bit puller of claim 21,wherein the handle comprises a hand grip at an end thereof.
 23. A miningbit puller for extracting mining tool bits, the puller comprising a bitpuller plate including two forks at a front end of the plate and a backend of the plate structured and arranged to receive a striking pad. 24.The mining bit puller of claim 23, wherein the back end of the bitpuller plate comprises a threaded hole for receiving a threaded bolt ofthe striking pad.
 25. The mining bit puller of claim 23, wherein theback end of the bit puller plate comprises a recess for receiving atleast a portion of the striking pad.
 26. The mining bit puller of claim25, wherein the recess is circular.
 27. A striking pad for a mining bitpuller, the striking pad comprising: a striking surface; and means forconnecting the striking pad to the mining bit puller.
 28. The strikingpad of claim 27, wherein the connecting means comprises a mechanicalfastener.
 29. The striking pad of claim 27, wherein the connecting meanscomprises a threaded bolt extending from an opposite side of thestriking pad from the striking surface.
 30. The striking pad of claim27, wherein the striking pad comprises an extended portion structuredand arranged to be received in a recess of the mining bit puller. 31.The striking pad of claim 30, wherein the extended portion has acircular cross section.
 32. The striking pad of claim 30, wherein theextended portion has an axial length smaller than an axial length of theremainder of the striking pad.
 33. The striking pad of claim 27, whereinthe striking pad comprises a metal plate and a resilient material, andthe resilient material at least partially surrounds the metal plate andcovers the striking surface.